Automatic firearm with recoiling barrel and without movable breech



1929- G. MASCARUCCI 1,733,231

AUTOLFATIC FIREARM WITH RECOILING' BARREL AND WITHOUT MOVABLE BREECH Filed Feb. 15, 1928 Patented Get. 29, 1929 GIUSEPPE MASCARUCCI, OF TURIN, ITALY, ASSIGNOR TO SAFAT SOCIETA ANONIMA FABBRIOA ABMI-TORINO, 01E TORINO, ITALY, A SOCIETY OF ITALY AUTOMATIC FIREARM WITH RECOILII TG- BARREL AND WITHOUT MOVABLE BREEOH Application filed February 15, 1928, Serial No. 254,561, and in Italy February 24, 1927.

In automatic firearms with a recoiling barrel in use at the present time, the obturator is opened and consequently the e ectlon of the case of the discharged cartridge effected 6 and the new cartridge inserted in the chamber of the barrel, by means of a group of members through the medium of which a breech movable in the interior of a frame and rigid with the barrel causes a mechanical member forming a lock between the breech itself and the obturator to be disengaged. When this disengagement is completed the obturator remains free and under the action of the kinetic energy it possesses and the small pressure of the gases which remain in the barrel, it continues its recoil stroke, causing the cartridge case to be e ected and the striker to be cocked. During the return stroke the obturator inserts in the chamber of the barel a new cartridge taken from the magazine or from the leading device or from the feeding belt, or inserted in the firearm in any manner. Finally, the obturator provokes the release of the striker.

The whole arrangement formed by these parts, the frame, breech, barrel, obturator, locking device and striker, and also accessory parts related thereto, forms a very heavy arrangement which is delicate and costly to manufacture because all these parts must be tempered and nearly always trued up by grinding.

Now the object of the present invention is to eliminate the most costly and most delicate of these members, that is to sav, the movable breech, and it has for its subject matter a direct locking device between the barrel and obturator comprising a member for producing a direct locking between the said parts which is connected to the barrel and is also connected to the frame through the medium of members controlling its movement and such as to provoke the disengagement of the obturator from the gun barrel automatically only when the said parts have travelled together a determined portion of the recoil stroke and precisely at the moment when, the projectile having left the its kinetic energy, continue its recoil stroke gun barrel, the obturator can, by virtue of and perform all its successive functions.

Some embodiments of the subject of the invention have been illustrated diagrammatically and simply by way of example in the accompanying drawing in which:

Figs. 1 and 2 are vertical sections taken along the longitudinal axis of an automatic firearm, rifle or machine gun, showing a first form of the arrangement of the barrel, the obturator and the locking device, in the closed and open positions respectively.

Figs. 3, 4 and Figs. 5, 6 illustrate two modified constructions in a similar manner.

In this drawing 1 is the fixed frame of the firearm in the interior of which are mounted in such a way that they are adapted to slide under the action of the recoil, both the barrel 2 and the obturator 3. The stroke of the barrel is limited bya stop of any kind which in the forms shown in Figs. 1 to 4 is formed for example by a pin 4 rigid with the lug 2' of the barrel and moving in the interior of a slot 1 of suitable length formed in the frame.

In the first form of construction shown in Figs. 1 and 2, the direct locking device between the barrel and the obturator comprises a lever 5, which in the following description will be called the locking lever or member, which is pivotally connected to the barrel and is for example, mounted so that it can oscillate freely upon the pin 4. The lever 5 is adapted to engage, in the closed position, by means of the tooth 5, upon the shoulder 3 of a notch formed in the body of the obturator, thus holding the latter locked relatively to the barrel. This same lever 5 is also connected to the fixed frame 1 of the firearm by means of a link 6 pivotally connected to the pivot 5 rigid with the lever 5 and to the pivot 7 rigid with the said frame. The position of this pivot 7 may be varied, between certain limits, by moving this same pivot along a suitable slot 8 formed in the wall of the frame and then securing it in the desired position.

The operation is as follows During the first portion of the recoil stroke the barrel 2 and the obturator 3 which are mutually locked, move together until the locking lever 5, as a consequence of the link 6 which connects it to the pivot 7 rigid with the frame, is raised and its tooth 5' is disengaged from the shoulder 5 (see Fig. '2). The obturator 3 is then free to continue its recoil movement while the barrel stops as soon as the in 4 presses against the end of the slot 1. The obturator thus completes the total recoil stroke during which it causes the cartridge case to be ejected and the striker to be cocked; then, under the action of the usual recuperating spring, the obturator is returned forward and causes a new cartridge to be inserted in the chamber of the barrel. The barrel is pushed back into its initial or firing position while the locking lever 5 again engages with its tooth 5 behind the shoulder 3 thus locking the parts once more as shown inFig. 1. The release of the striker and the commencement of a new cycle of operations can then take place.

y varying the position of the pivot 7 along the slot 8 it is possible to arrange for the tooth 5 to leave the retaining shoulder 3 after the barrel and the obturator have travelled together over more or less long spaces. More exactly, starting from the position the pivot occupies in Fig. 1, if it is displaced downwards an advance in the dis engagement between the barrel and the obturator is produced while if it is displaced upwards a lag is produce. This permits the amplitude of the recoil of the barrel necessary for effecting the disengagement between the barrel and the obturator to be regulated, exactly as is required in practice for the adjustment of the firearm when as a result of use the rifling's of the barrel have undergone a certain amount of wear.

The above described arrangement completely eliminates a member existing in machine guns with a recoiling barrel known up to the present time, that is to say, the movable breech which nearly always necessitated very complicated working operations and special heat treatments for the purpose of making it capable of lasting for a long time. This arrangement'further permits the firearm to be considerably simplified by making it lighter, less costly and more easy to manipulate.

While leaving una tered the fundamental principle on which the present invention is based, the locking device itself is adapted to assume various forms from the constructional point of view.

Thus for example, as shown in Figs. 3 and 4, the locking lever 5 may be connected to the frame by means of a pivot 5 adapted to slide in a slot 9 inclined relatively to the direction of the movement of recoil and formed in the frame or in a plate 9 adapted to be secured in a suitable position upon the frame itself. By means of this arrangement when'the barrel recoils the locking lever 5* is raised and disengaged from the obturator (see Fig. 4) in a manner similar to that described above. The slot 9 may also vary in form from the rectilinear shape shown in the drawing; for instance, its commencement may have an inclination which may be different from that of the remaining part of the slot itself and for example, be smaller than the latter. Even in this case, by suitably varying the relative position of the slot 9 with respect to the plate 9 relative to the frame 1, the locking lever 5 may be made to disengage after a recoil stroke of varying length of the barrel 2, this being done always for the purpose of regulating the firearm as specified above.

The locking member, instead of having the form of a lever, may also adopt the form of a slider as shown in Figs. 5 and 6. In this case the slider is connected to the frame 1 by means of lateral ribs 5 engaging with slots 1O inclinec relatively to the direction of movement of the recoil and formed in the walls of the frame or in plates mounted upon these walls. This slider is constantly in engage ment by means of its tooth 11 with a retain ins; shoulder 12 on the barrel 2 while by means of another shoulder with which it is provided it engages behind the shoulder 3' of the obturator 3 thus locking it whenthe barrel is in the firing position 5). lW hen the barrel recoils the slider is forced backwards and by engaging with the slots 10 it is also raised so that-after a certain portion of this recoil the obturator becomes disengaged (see Fig. 6). Even in this case by varying the relative position of the inclined slots 10 the value of the recoil stroke of the barrel which is necessary for producing the disengagement may be varied.

It is obvious moreover, that the present 1nvention is in no way limited to the exact arrangements described and illustrated but that without going outside its scope it may undergo all modifications which circumstances or requirements of practice may cause to be con sidered necessary or advantageous.

I claim: 1. In an automatic fire-arm, a casing, a

sliding barrel therein operated by recoil, a.

breech having a shoulder on its forward end, a hook member carried by the rear end of the barrel for engagement with the shoulder on the breech, and means on the casing to guide the hook member out of engagement with the shoulder on the breech and permit the breech to continue its rearward movement.

2. In an automatic fire-arm, a casing having opposite slots, a sliding barrel therein operated by recoil, a breech having a shoulder thereon, a pin in the barrel extending laterally into said slots to limit the rearward movement of the barrel in the casing, a hook on the pin to engage said shoulder, and guide means on the casing to disengage the hook from the shoulder and permit the breech to continue its rearward movement.

3. In an automatic fire-arm, a casing; having opposite straight slots and an adjustment slot, a breech having a shoulder, a transverse pin on the rear end of the barrel whose ends extend into said straight slots and limit the rearward movement of the barrel. a hook on said pin to engage the shoulder of the breech, a link pivoted to the hook at one end and a pin in the opposite end of said link and adjustable in said adjustment slot to lift the hook from said shoulder upon the recoil of the barrel and permit the breech to complete its rearward movement.

4. An automatic firearm having a recoiling barrel and without breech body. characterized by a direct locking device between the barrel and the breech block, comprising a locking member pivotally attached to the barrel and terminating in a projection, a shoulder on the breech block engaged by said projection, a link connected at one end to the locking member and the other end of which is adapted to pivot about a pin rigid with the stationary frame of the firearm to automatically release the breech.

5. An automatic firearm as claimed in claim 4, in which the pin rigid with the stationary frame about which pivots the link pivotally connected to the locking member, is adjustable in position for the purpose of varying as desired the amplitude of the recoil of the barrel necessary for effecting the automatic release of the breech block.

In testimony that I claim the foregoing as my invention, I have signed my name.

GIUSEPPE MASOARUCCI. 

